Bar code scanners are used in a wide variety of applications that rely on bar codes to store information. Industries such as retail, airline, self-service, automotive, parcel delivery, pharmaceutical, healthcare and others use bar codes to provide inventory control, customer identification, item tracking, security and many other functions. A typical bar code is comprised of a number of bars separated by spaces. Information is encoded on a bar code by varying the width of the bars and spaces. When a bar code is placed within the field of view of a bar code scanner, the scanner will detect, analyze and decode the bars and spaces comprising the bar code to retrieve the information encoded wherein. This operation is also called scanning or reading a bar code. The information encoded on a bar code is usually a sequence of numeric or alphanumeric numbers (e.g., a Universal Product Code (UPC) or European Article Number (EAN)).
An imaging bar code scanner (also referred to as an image scanner) reads a bar code by capturing a digital image of the bar code and then processing the image to detect and decode the bar code. It is advantageous for the bar code scanner to successfully read all bar codes presented to the scanner on the first pass of each bar code by the scanner. This is known as a successful first pass read. Successful first pass reads of bar codes helps to maintain a good workflow at the checkout station and speeds up the overall checkout process. A high first pass read success rate has also been found to reduce stress on the person operating the scanner. This is particularly true if the operator is a customer operating a self-checkout terminal.
High performance passby barcode scanners based upon image capture and image processing technology have been slow to be adopted in passby scanning environments. In a retail environment, an image scanner must achieve a passby speed of 30 to 50 inches per second. The image scanners on the market today have not proved capable of such speeds, which is why laser based barcode scanners dominate the passby scanning environments.
One important barrier that has prevented image scanners from reaching such high passby speeds is the large amount of pixel information involved with each image and the time required to transfer, process, and decode pixel information captured by an image capture device. Current image capture devices have limited methods for reading captured image data. As a result, more data is read from the image capture device than is needed.
Therefore, it would be desirable to provide an image capture device that does not suffer from these problems.